Modulated Bi-Directional Zero Voltage Transient AC/DC Converters

Abstract

A zero voltage transient cell comprising (i) one high switching frequency mosfet, (ii) two low switching frequency mosfet or two insulated-gate bipolar transistors, (iii) four diodes, (iv) one capacitor; and (v) one inductor or one additional diode in series with the inductor, which zero voltage transient cell can be used in a bi-directional AC/DC converter with switches and in a method of modulation that causes no switching loss in the conversion of AC to DC or DC to AC. The bi-directional AC/DC converter with the zero voltage transient cell can be used in a vehicle onboard charger.

What is claimed is: 
     
         1 . A zero voltage transient cell for integrating in devices, the zero voltage transient cell comprising:
 (a) one high switching frequency mosfet, which switches on before two main switches and off simultaneously with the two main switches, the high switching frequency mosfet providing a current pathway to an inductor;   (b) two low switching frequency mosfets or two insulated-gate bipolar transistors, which are used to prevent current conducted from other components during DC to AC mode;   (c) four diodes, which are used to prevent reverse current from the inductor and voltage spikes;   (d) the capacitor, which is used to provide additional capacitance for the two main switches;   (e) the inductor, which is used as a current storage device to keep current flowing;   wherein the zero voltage transient cell is capable of providing soft switching for the devices it is integrated in.   
     
     
         2 . A zero voltage transient cell for integrating in devices, the zero voltage transient cell comprising:
 (a) one high switching frequency mosfet, which switches on before two main switches and off simultaneously with the two main switches, the high switching frequency mosfet providing a current pathway to an inductor;   (b) two low switching frequency mosfets or two insulated-gate bipolar transistors, which are used to prevent current conducted from other components during DC to AC mode;   (c) four diodes, which are used to prevent reverse current from the inductor and voltage spikes;   (d) the capacitor, which is used to provide additional capacitance for the main switches;   (e) the inductor, which is used as a current storage device to keep current flowing;   (f) one additional diode in series with the inductor, which is used to prevent reverse current from the inductor and voltage spikes; and   wherein the zero voltage transient cell is capable of providing soft switching for the devices it is integrated in.   
     
     
         3 . A bi-directional AC/DC converter having switching, the AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell comprising:
 (a) one high switching frequency mosfet, which switches on before two main switches and off simultaneously with the two main switches, the high switching frequency mosfet providing a current pathway to an inductor;   (b) two low switching frequency mosfets or two insulated-gate bipolar transistors, which are used to prevent current conducted from other components during DC to AC mode;   (c) four diodes, which are used to prevent reverse current from the inductor and voltage spikes;   (d) the capacitor, which is used to provide additional capacitance for the main switches;   (e) the inductor, which is used to provide additional capacitance for the main switches; and   wherein there is no duty cycle jumping and the zero voltage transient cell provides soft switching for all of the switches of the bi-directional AC/DC converter with no switching loss.   
     
     
         4 . A bi-directional AC/DC converter, the AC/DC converter having switching, the AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell comprising:
 (a) one high switching frequency mosfet, which switches on before two main switches and off simultaneously with the two main switches, the high switching frequency mosfet providing a current pathway to an inductor;   (b) two low switching frequency mosfet or two insulated-gate bipolar transistors, which are used to prevent current conducted from other components during DC to AC mode;   (c) four diodes, which are used to prevent reverse current from the inductor and voltage spikes;   (d) the capacitor, which is used to provide additional capacitance for the main switches;   (e) the inductor, which is used to provide additional capacitance for the main switches;   (e) one additional diode in series with the inductor to prevent reverse current from the inductor and voltage spikes; and   wherein there is no duty cycle jumping and the zero voltage transient cell provides soft switching for all of the switches of the bi-directional AC/DC converter with no switching loss.   
     
     
         5 . A method of modulating the converting of AC to DC and DC to AC with a bi-directional AC/DC converter with switching, the method comprising:
 (1) converting AC to DC by (a) inputting AC to the bi-directional AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell comprising (i) one high switching frequency mosfet, (ii) two low switching frequency mosfet or two insulated-gate bipolar transistors, (iii) four diodes, (iv) one capacitor; and (v) one inductor; and (b) outputting DC, wherein the converting of AC to DC causes no duty cycle jumping and no switching loss in the bi-directional AC/DC converter; and   (2) converting DC to AC by (a) inputting DC to the bi-directional AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell of part (1); and   (b) outputting AC, wherein the converting of DC to AC causes no duty cycle jumping and no switching loss in the bi-directional AC/DC converter.   
     
     
         6 . A method of modulating the converting of AC to DC and DC to AC with a bi-directional AC/DC converter with switching, the method comprising:
 (1) converting AC to DC by (a) inputting AC to the bi-directional AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell comprising (i) one high switching frequency mosfet, (ii) two low switching frequency mosfet or two insulated-gate bipolar transistors, (iii) four diodes, (iv) one capacitor; (v) one inductor, and (vi) one additional diode in series with the inductor; and (b) outputting DC, wherein the converting of AC to DC causes no duty cycle jumping and no switching loss in the bi-directional AC/DC converter; and   (2) converting DC to AC by (a) inputting DC to the bi-directional AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell of part (1) and (b) outputting AC, wherein the converting of DC to AC causes no duty cycle jumping and no switching loss in the bi-directional AC/DC converter.   
     
     
         7 . A vehicle onboard charger comprising a bi-directional AC/DC converter with switching, the bi-directional AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell comprising (i) one high switching frequency mosfet, (ii) two low switching frequency mosfet or two insulated-gate bipolar transistors, (iii) four diodes, (iv) one capacitor; and (v) one inductor, and wherein the converting of AC to DC and DC to AC causes no duty cycle jumping and no switching loss in the bi-directional AC/DC converter. 
     
     
         8 . A vehicle onboard charger comprising a bi-directional AC/DC converter with switching, the bi-directional AC/DC converter comprising a zero voltage transient cell, the zero voltage transient cell comprising (i) one high switching frequency mosfet, (ii) two low switching frequency mosfet or two insulated-gate bipolar transistors, (iii) four diodes, (iv) one capacitor; (v) one inductor; and (vi) one additional diode in series with the inductor, and wherein the converting of AC to DC and DC to AC causes no duty cycle jumping and no switching loss in the bi-directional AC/DC converter.